In general, there are two types of hinge devices. In the first type, respective one end parts of the first and second hinge members are turnably connected to each other, and in the second type, support arm parts are formed on opposite end parts of the first hinge member, respectively and opposite end parts of a second hinge member are turnably connected to the support arm parts, respectively. In the former hinge device, the first and second hinge members are connected to each other in a cantilever fashion, and in the latter hinge device, the second hinge member is connected to the first hinge member in a two-spot supporting fashion. Accordingly, the latter hinge device is suited to be used for a heavy-weighted door and the like. The present invention relates to the latter hinge device.
In the conventional two-spot supporting hinge device, the respective support arm parts of the first hinge member attached to the skeleton, and the opposite end parts of the second hinge member attached to the door are turnably connected to each other through a damper unit. This damper unit prohibits the door from turning at a high speed at the time the door turns at least in one direction of opening and closing directions, for example, closing direction. This is intended to prevent an unexpected accident which is likely to occur when a large-sized door turns at a high speed (for example, see Official Gazette, page 6 to 7 and FIG. 3 of Registered Japanese Utility Model No. 3,039,413).
In the above-mentioned conventional two-spot supporting type hinge device, a stator and a rotor constituting the damper unit are fitted to a support arm part of the first hinge member and an end part of the second hinge member, respectively, thereby turnably connecting the first and second hinge members. However, the number of the places for turnably fitting the first and second hinge members to each other becomes large in such a connecting construction as mentioned above, because the stator and the rotor are turnably fitted to each other and the stator and the rotor are fitted to the support arm part and the second hinge member, respectively. Therefore, there is such a problem that play tends to occur between the first hinge member and the second hinge member. Moreover, since the damper unit is comparatively low in rigidity, the conventional two-spot supporting hinge device has such a disadvantage as to lack strength when it is used for a heavy-weighted, large-sized door.